Echoing a common complaint in the impoverished swampland that produces most of Nigeria's oil, the protesters said they were not benefiting from the region's oil wealth and wanted an end to the oil pollution that has ruined much of the land.

Soldiers and security guards did not disperse the crowd as it entered the Belema Flow Station in Rivers State, which feeds oil into Shell's Bonny export terminal.

The company said it had evacuated staff late on Thursday and shut the facility when it became clear the protesters were on their way there.

However, the army sent in 30 extra soldiers after protesters said they planned to stay at the facility for two weeks.

One of the protest leaders, Anthony Bouye, said: "I am a graduate for about eight years without a job. Shell won't employ me despite us having so much wealth in our backyard."

Shell said its "commitment to the welfare of host communities in the Niger Delta remains unshaken" and was working with authorities to resume operations at the facility.

Supplies of Bonny Light crude oil are already limited as the Trans Niger Pipeline is closed, although exports have continued using Nembe Creek Trunk Link pipeline.

Militant attacks on oil facilities have largely stopped since the government started talks with community leaders in 2016 to address locals' grievances.

But protests still flare as residents complain they are not benefiting from the Delta's energy wealth, the main source of Nigeria's government revenue.

Oil exports were scheduled to hit a 17-month high in August, but fell back under 2 million barrels per day (bpd) after Shell declared force majeure on Bonny light.

Nigerian oil production fell to just over 1 million bpd at certain times last year but has recovered thanks to a steady decline in the number of attacks on pipelines.

(Reporting by Tife Owolabi; Additional reporting by Libby George in London and Alexis Akwagyiram in Lagos; Writing by Ulf Laessing; Editing by Louise Ireland)